Expansion plug for lamp sockets



Feb; 19, i924;

A. C. CARSON EXPANSION PLUG FOR LAMP SOCKETS Filed July 7. 1921 Patent et. l, 1924.(

` lTED STATE t rc.

EXPANSION ELUG EOE MCKETS.

Application led Iuly 7,

To all whom it may concern Be it known that I, AsHMmD C. CARSON,

a citizen of the United States, residing at` Columbiaz in the county of Richland and a State of eouth Carolina, have invented certain new and useful Improvements in Expansion Plugs for Lamp Sockets, of lwhich the following is a full, clear, and exact description.

Myinvention relates to plugs for lamp sockets, and has for its object to provide such a plug with means whereby it may be expanded or contracted when being applied to or withdrawn from the socket and therela by avoid the loss of time required to screw into place the ordinary plugs now in use,

and also avoid twisting the connecting wires.

Another object of the invention is to provide such a plug with its parts so located ao and arranged as to avoid any shocks to the person mani ulating it.

Another o ject of the invention is to provide such a plu with contacts for connection with the or inary standard cap having at parallel contacts.

@ther and further objects of the invention will be apparent from the followin description when taken in connection wit the accompanying drawings, in which:

Figure 1 is a vertical section through the phg. l

1gure 2 is a perspective view of the plug and expanding ar separated, and

Figure 3 is a perspective view of details. Referring to the drawings more in detail, the numeral 1 designates t e ordinary lamp socket now in common use and to which my plug, designated generally by the numeral 2, is adapted to be applied. an The screw threaded sleeve 3 extends only part way around the plug 2 and the exposed part of the plug is beveled od or made of less curvature, as shown at l, so that the plug ma easily be inserted and removed from the ce soc et.

rl`lhe plug is provided with a longitudinal slot indicated at 5, and pivoted between the walls of this slot on pin 6 is an expanding arm 7. rllhis arm is provided with threads w at its up er end to engage the threads of the socket. ecured to the lower end of the expending arm 7 is a leaf spring 8. Extending transversely .of the slot y is a pin 9. The

1921. erial lilo. 458,@12.

free, end'of the sprinS engages under the pm 9 and thereby to limit the outward movement of the expanding arm 7.

Pivoted in a slot 10 of the expanding arm 7 is a cam member 11. The cam portion of the cam member ll operates on the surface of the spring 8 and in this manner the cam is prevented from cutting the insulation. The cam is arranged so that pressure on the handle or push button thereof away from the socket will expand the -arm 7, and a reverse movement will .contract the arm. The wires 12 are attached to the conduct- 1ng strips 13 secured in the plug. The conducting strips 13 are arranged in the usual manner, one extending through the end of the plug and the other being attached to the side thereof. Laterally extending contacts 14 are formed on the strips 13 for the pui'- pose of receiving the contacts of the ordinary attachment plug 15 having parallel contacts 16.

The plate 17 and insulating strip 18 are provided with openings 19 and 20, respectively, to receive the contacts 14 and 16,. 1repectively, of` plug 2 and attachment plug 15.

late 17 and strip 18 are secured in place by means of suitable screws 21.

The plug 2 is provided with a flange 22 and i the expanding arm 7 is provided with a Hange 23, the two flanges together forming a circular abutment on the plug which prevents the hand ot the operator from coming in contact with the socket to which the plug is being attached.

ln operation it is only necessary to move the handle or push button oi the cam l1 toward the head of the socket and thereby contract the 4expanding arm 7. rllhe plug can then be inserted in the socket and a reverse movement of the handle or push button will expand the arm 7 and lock the plug se. curely in place.

While ll have shown the 15 as connected to the Side if desired, be attached to plug.

ln accordance with the patent statutes, ll have described what l nora .believe to be the best embodiment et the invention, but ll do not wish to be understood thereby as limiting myself` or the scope of the invention, as many changes :and modifications may be attachment plug oit plug 2, it may, the end of this lll@ lltlti made Without departing :imm the snirit the invention; ail nach aim t@ include in the scope ai the appended claimsg What l claim as new and desire to secure by Let'ers is:

l. in an expanding plug, a hody portion,

an arm pivoted on said body portion, a leaf spring secured to said arm and extending longitudinally thereof and a pin on the body to engage the spring and limit the movement of the arm.

2.` 'In an expanding plug, a body portion, an arm pivoted thereon, a spring secured to said arm, and a. cam for moving said arm, said cam engaging the s ring.

A3. In an expanding p ug, a substantially cylindrical body portion having a longitudinal channel therein, an arm pivoted in said channel, resiiient means normally hoidiaig the ire@ end of the arm Within the groove,

and a cara for forcing the free and of t Le arm rtly ont of the groove.

d. an expanding .plugga substantiaii cylindrical body portion having a longitudinal channel ou lts outer wall, an arm ivoted in said channel, a leaf spring secure to the inner surface of said arm, and a pin extending across said channel l and engaging the free end of said s ring.'

, 5. In an expan ing plug, a body portion having a channel thereln, an arm pivoted in said channel, a spring on said arm, a in engaging the free end of thespring, an a cam or movlng the arm on lts pivot. A

-ASHMEAD C. CARSON. 

